The invention relates to a method for preparing cattle feed mixtures as defined in the introductory portion of claim 1 and to a device for implementing the method as defined in the introductory portion of claim 10.
For reasons of feed hygiene, it is desirable that an cattle feed, particularly a liquid feed, has a pH, which is between 4 and 5 and preferably at about 4.5. The invention is concerned with the problem of influencing the pH of the feed mixtures, especially of correspondingly large batches in weighing and mixing containers of feed stations of feeding devices. The invention solves the problem with a method of claim 1 and with a device of claim 10. With respect to further refinements, reference is made to claims 2 to 5 as well as 10 to 12.
The inventive method ensures that, during the preparation of the feed mixture the pH of this feed mixture is determined and, if it is too high, lowered in a specified manner by a gradual addition of acid. Since the addition of acid takes place at the conclusion of the actual preparation process of a batch, it is ensured that there are no further pH changes after the pH is adjusted due to the addition of further feed components. For carrying out the method, the invention furthermore provides a weighing and mixing container, which is provided in the lower region with a pH measuring probe, which is passed through the wall of the container. The sensor of such a measuring probe accordingly lies in a region of particularly intensive feed flow, similar to that which builds up in the course of the mixing process under the action of the conventional stirrer in the weighing and mixing container. Accordingly, it is ensured that pH changes, which occur, are determined rapidly, so that the desired final value in the feed batch can be obtained precisely.